Search publications of the members of the Royal Belgian institute of natural Sciences
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Former Katanga Province in the Democratic Republic of Congo – rich in diversity and life! Preliminary results on freshwater fish parasite diversity
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Capacity building for an assessment of the impact of mining in Katanga (D.R.Congo) on fishes and their aquatic habitats
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Pelagic freshwater fish parasites in Lake Tanganyika: do the monogeneans mirror host origin?
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A hitchhiker’s guide to tilapia: How parasites take a ride on introduced Nile tilapia in the DR Congo
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Decline in parasite diversity promoted by lower host densities in Lake Tanganyika
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Quantification of hydrodynamic changes induced by an offshore mussel aquaculture farm using COHERENS (Part 2)
- The goal of this numerical study is the quantification of hydrodynamic changes (especially sea currents) induced by an offshore aquaculture farm similar to that of the industrial project “Westdiep Sea Farm”. To do that, a parameterization of the impact of longlines and droppers on hydrodynamics has been included in the 3D COHERENS hydrodynamic model and the impact of several configurations of the aquaculture farm on currents and bottom shear stress has been estimated in a simplified test case. In this previous internship project, a numerical study to quantify the impacts of an offshore aquaculture farm on hydrodynamics processes has been performed. To do so, a new module has been developed in the COHERENS model to compute the drag forces exerted by the droppers and then this module has been applied on a simplified case study, i.e. a modest farm with up to 40 longlines of 104 droppers and located in a straight open channel of 500 m width and 2 km length. The simulations show that, in all configurations tested, the presence of droppers significantly changes the hydrodynamics of the channel. Particularly, analysis of the bottom shear stress variations allowed to conclude that the presence of a modest offshore aquaculture farm could modify the erosion/sedimentation pattern around the farm, leading, for example, to a risk of destabilization of the neighbouring sandbanks, which would justify the implementation of an environmental monitoring program. Nevertheless, this previous work remains a preliminary study and many simplifications have been applied in order to obtain results in the given time. This second work (Part 2) will allow to refine the physics of the test channel in order to make it more realistic and to obtain results more faithful to the hydrodynamic reality in the North Sea. In this report, different sensitivity studies will be carried out mainly for the first phase of the project. Several metrics will be illustrated. Then, comparisons between the different phases will be made.
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D4.2 Improving the prediction of HNS concentration in the atmosphere
- Responding to maritime accidents can be extremely challenging when involving HNS that behave as evaporators. Due to their potential to form toxic or combustible clouds, evidence-based decisions are needed to protect the crew, responders, the coastal population and the environment. However, when an emergency is declared, key information is not always available for all the needs of responders. A case in point is the lack of knowledge and data to assess the risks that responders or rescue teams could take when intervening, or those that could impact coastal communities when allowing a shipping casualty to dock at a place of refuge. The MANIFESTS project aims to address these uncertainties and improve response and training capacities through the development of an operational decision-support system (DSS) for volatile HNS spills. Besides management and communication, the project includes four other work packages: WP2 on collecting new data on evaporators, WP3 on table top exercises and field training, WP4 on improving modelling tools and WP5 on the development of the DSS. Key expected outcomes include: · Operational guidance; · Desktop and field exercises; · In situ training; · Experimental data on gas cloud fate; · A brand-new fire and explosion modelling module; · Improved HNS database with new experimental data on evaporation/dissolution kinetics. This report presents the developments realized in the framework of the task 4.2. This task gave the opportunity to the MANIFESTS consortium to improve one or several features of their models allowing to better simulate the HNS concentration in the atmosphere. Only RBINS seizes this opportunity and has implemented in OSERIT some improvements in order to better simulate the HNS concentration at the sea surface, evaporation processes and finally has implemented a new atmosphere transport and dispersion model. OSERIT (Oil Spill Evaluation and Response Integrated Tool) is a model which describes the drift of a pollutant at sea using Lagrangian particle. It can be used in case of an accident with release of oil or chemical, to obtain an estimation of the pollution trajectory as well as some basic information about its behavior and fate at sea. In the framework of the MANIFESTS project, a new atmospheric dispersion module fully coupled to OSERIT has been developed and several marine processes have been improved. In this report, the improved processes are described and their actual implementation in OSERIT is explained.
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D4.3 - Models intercomparison
- Maritime transport represents more than 80% of the international trade volume (UNCTAD, 2017). Apart from crude oil, tanker trades of refined petroleum products, chemicals and gas have increased by 4% over the 2019-2021 period, with a 5.6% growth in Liquefied Natural Gas (LNG) trade (UNCTAD, 2022). The volume of hazardous and noxious substances (HNS) is thus constantly rising with an increased risk of accidental spillages potentially associated with marine pollutions, whether in ports or in the open sea. In the event of an incident and a spill in the environment, information on the fate of the chemical(s) involved is essential to better anticipate the risks incurred by responders and populations, the impacts on the environment as well as the appropriate response techniques (Mamaca et al., 2009). Chemicals accidentally spilled into the marine or aquatic environment generally undergo physical-chemical modifications that will characterize their behaviour and fate. As observed by Mamaca et al. (2004) and Le Floch et al. (2011), these modifications are dependent on the intrinsic parameters of the product involved, the in situ environmental parameters (temperature, density and salinity of the water) and the met-ocean conditions (e.g. sea state, wind speed, marine currents). A few hours following the spill short-term effects may thus occur such as spreading, natural dispersion in the water column (dissolution, emulsification) and evaporation into the atmosphere. Longer term degradation (e.g. polymerisation, biodegradation) and sedimentation processes can then follow, depending on the persistence and the nature of the substance. One of the main concerns is that around 2,000 different types of HNS are regularly shipped in bulk or package forms (Purnell, 2009) which thus make difficult to capture their behaviour if accidentally released in the environment. Of the wide variety of HNS traded, volatile and gaseous substances are particularly problematic for marine pollution response authorities. The release of such substances at sea can indeed lead to the formation of toxic, flammable, or explosive gas plumes – sometimes invisible to the naked eye – that can travel large distances and pose risks over a wide area in relatively short timescales. Yet, key information on the risks that responders or rescue teams could take when intervening, or those that could impact coastal communities and the environment when allowing a shipping casualty to dock at a place of refuge remain poorly known. The MANIFESTS EU-project is part of this context.
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D4.4 - Model validation
- The transportation of hazardous and noxious substances (HNS) on ships has been on the rise in recent years, posing a significant threat to both human health and the environment. The spill of these chemicals can have far-reaching consequences, particularly when dealing with highly volatile substances that can spread rapidly and unpredictably. The MANIFESTS project has been established with the goal of better understanding the behaviour of these substances to improve response capabilities in the event of a spill. Through research and analysis, the project aims to improve already existing models for predicting the behaviour of HNS in various environments, and to validate these models through a series of experiments and real-world scenarios. Models are essential tools to understand and predict the behaviour of HNS in the event of a spill. However, they are not perfect and have limitations in terms of accuracy, which must be considered by the users. During the MANIFESTS project, the models CHEMMAP, OpenDrift, OSERIT, and MOHID, have been utilized and compared against separate sets of data. These models will be introduced briefly in the next section. This report consists of three validation sections. The first section compares a small-scale laboratory experiment that visualizes the competition between evaporation, dissolution, and volatilization, and assesses the model's ability to simulate these processes. The second section investigates the impact of wind on the evaporation rate and provides as much environmental data as possible to the model, using a wind tunnel. The two last section of this report compares the models' simulation with the sea trials that took place at the end of May 2022. These sections compare both the drift in the water and the air dispersion against field data. By analysing these different experiments, we can understand the capabilities and limitations of the models used in this project.
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D5.2 - MANIFESTS DSS - Installation guides
- This technical deliverable explains the installation details of the decision support tools developped during the MANIFESTS project "MANaging risks and Impacts From Evaporating and gaseous Substances To population Safety". These tools includes: - The MANIFESTS Common Operational Picture and its viewer (COP tool) - The MANIFESTS models web application
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D5.3 - MANIFESTS DSS - User guides
- This technical deliverable explains the utilisation of the decision support tools developped during the MANIFESTS project "MANaging risks and Impacts From Evaporating and gaseous Substances To population Safety". These tools includes: - The MANIFESTS Common Operational Picture and its viewer (COP tool) - The MANIFESTS models web application for the fire module, explosion module and for OSERIT HNS - The HNS database
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D5.4 - Proof of concept of MANIFESTS DSS
- This technical report is a proof of the availability of the service developed and improved during the MANIFESTS project "MANaging risks and Impacts From Evaporating and gaseous Substances To population Safety". It include the models for the fire, explosion, OSERIT object, OSERIT HNS and OSERIT OIL
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Preliminary report on weathering
- This is a list of several parametrizations related to the weathering of oil. This is mainly a work document with references.
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New insights into cave hyena ethology and the implications for territorial competition with hominins in Late Pleistocene north-west Europe: the case of Caverne Marie-Jeanne (Belgium)
- Megacarnivore behaviours shape ecological dynamics between their prey and competitors and therefore play a key role in structuring ecosystems. In Late Pleistocene Eurasia, hominins and hyenas were sympatric predators. Since the first discoveries of Crocuta c. spelaea in the 19th century, this ‘bone-crushing’ species has been identified at most Palaeolithic sites and has inspired many taphonomic studies. Nonetheless, there is still very little known about its reproductive, social and spatial behaviours. We believe that exploring the complexity of the cave hyena's ethology is a way to better understand spatial relationships and niche sharing/partitioning between hominins and other top predators in Pleistocene ecosystems. This paper focuses on the study of Caverne Marie-Jeanne Layer 4 (Hastière, Belgium), one of the best-preserved palaeontological sites in the region. The exceptional number of hyena neonates in this assemblage (minimum number of individuals 300) has led us to describe, for the first time, a Late Pleistocene hyena birth den that was reused over a long period of time around 47.6–43k a bp. By bridging the gap between archaeology and palaeontology, we explore the potential of carnivore socio-spatial organisation and denning habits as an ecological proxy and discuss how these new unique data could help us further understand hominins’ spatial strategy in southern Belgium.
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Description of Aspella lorenzi n. sp. (Gastropoda: Muricidae: Aspellinae) from the Northern Red Sea
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Middeleeuwse landbouw in Brussel: een natuurwetenschappelijke kijk (BHG)
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The diet of a household in late and post-medieval Brussels: multidisciplinary analysis of cesspits from café Greenwich, Brussels
- During renovation works in the cellar of a famous art nouveau building in the centre of Brussels -Café Greenwich- three late and post-medieval cesspits were discovered and excavated by the archaeological team of the Brussels-Capital region. Two cesspits, one dated to the 14th/15th century and the other to the beginning of the 16th century, still contained several layers of excellently preserved organic fll deposits. These were entirely sampled for archaeozoological, palynological, macrobotanical and paleoparasitological analyses. Some individual coprolites were collected for analyses as well. The integrated study gives information on human diet and health, and waste management. Indirectly, it also sheds light on social and economic status. In medieval times cesspits were not only used as dump for human faeces but often to discard various domestic waste as well. However, the flls of the analysed Brussels structures seem to consist almost exclusively of cess. The sieving residue subsists largely of small fruit pips. Ceramics and other archaeological objects were rare. Densities of archaeozoological remains vary considerably from one layer to the other. The faunal record consists generally of very small bones, mainly fsh but also small songbirds and chicken and a large quantity of tiny unidentifable bone fragments affected by the digestive process. The macrobotanical study reveals a large variety of plant foods: more than 40 species of economic plants were observed. Analysis of pollen signifcantly enlarges this spectrum with diverse species from which only leaves and/or flowers have been eaten. Furthermore the palynological study suggests the consumption of honey. The plant spectrum comprises several exotic and more expensive products while the faunal assemblage points to more common households.
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Combining regional downscaling expertise in Belgium: CORDEX and beyond. Final Report. Belgian Science Policy (BRAIN-be).
- ABSTRACT Context In the context of the Paris Agreement, there exists a clear demand from different stakeholders for Climate services in Belgium. However, Belgium currently lacks the fundament for enabling such services. The CORDEX.be project brought together the Belgian climate and impact modelling research groups into one network as the first step towards the realization of climate services. It is based on the international CORDEX (“COordinated Regional Climate Downscaling Experiment”) project but the “.be” indicates it goes beyond for Belgium. The key to the foundation of national climate services is a combination of the existing expertise on high-resolution downscaling, local-impact models, ensemble dynamical and statistical downscaling, combined with links to international initiatives and stakeholder dialogue. This allows to address the propagation of climate change and uncertainty from the global to the local scale combined with a better representation of climate extremes. The climate network consists of nine partners using four upper-air Regional Climate Models and seven Local Impact Models. The CORDEX.be framework and guidelines are based on a user-oriented bottom-up approach. The CORDEX.be framework provides the first building block for a research network which could be extended, both nationally and internationally, with the objective of providing climate services. Objectives The main objectives of the CORDEX.be project were: 1. Contribute to the international climate community by participating to EURO-CORDEX by performing regional climate simulations over Europe. 2. Provide an ensemble of High-Resolution (H-Res) climate simulations over Belgium i.e. to create a small ensemble of high-resolution future projections over Belgium at convection- permitting resolutions. 3. Couple these model simulation to seven local-impact models for impact studies. 4. Present an overview of the ongoing climate modelling activities in Belgium. 5. Provide coherent climate information for Belgium targeted to end-users, backed by: (i) a unified framework for the H-Res climate runs and (ii) uncertainty estimations on the climate change signal; 6. Provide and present a climate-impact report for stakeholders and the general public that highlight the most important results of the project. Conclusions While Belgium does not formally have a national climate centre (Fonteyn, 2013), the CORDEX.be project provides a platform for data exchange and communication among the Belgian climate- 7Project BR/143/A2/CORDEX.be - Combining regional downscaling expertise in Belgium: CORDEX and beyond modelling groups. This is coordinated through the website euro-cordex.be. This website will be maintained and updated with new results and serve as a link between the Belgian activities and the international ones of the CORDEX project. In the context of the CORDEX.be project a wide range of climate model simulations has been performed that are collected on the CORDEX.be data hub at RMI and will serve as the basis of future impact studies. The model simulations are thoroughly validated by comparison with past observations and GNSS-derived products. Different climate impact studies have been performed in the context of CORDEX.be and are presented here. These include the impact of climate change on extreme precipitation for Belgium; maximum snow height for Belgium; urban parameters for Brussels; including outdoor labor productivity, excess energy consumption and heat stress due to heat waves; agricultural crop performance and yield for Belgium; and biogenic emissions for Europe and Belgium. Focusing on the future period 2070-2100 for the scenario with the largest greenhouse gas emissions (RCP8.5), the most prominent impacts of climate change for Belgium include: A strong increase in tropical days and heat wave days. An increase in winter precipitation and long extremely wet periods. Intensification of summer precipitation extremes, especially in urbanized areas. The precipitation intensity with hourly time scale and 10-year return period may increase up to 100%. For the Brussels urban environment: o An increase of a factor 3 to 4 in the number of heat waves. o Significant increase of heat stress for people living in the city of Brussels, up to twice as large as in the surrounding rural areas. o Significant impact on the outdoor productivity due to thermal discomfort. More specifically, a doubling of lost working days may be expected. o A doubling of days when air-conditioning is intensively used, impacting the urban energy consumption. An increased variability for biomass production and yields. Average yields for fodder maize and late potatoes will also decline. Severely reduced winter snow height maxima (above 500m altitude). An increase of 51% of biogenic emissions from isoprene with the highest emissions in the Ardennes and Campine forests (disregarding the CO 2 inhibition effect). Indications exist that there will be less hail events but increase of mean hail size. 8Project BR/143/A2/CORDEX.be - Combining regional downscaling expertise in Belgium: CORDEX and beyond A table including the climate change numbers and their uncertainty estimates for Belgium are provided. Based on interactions and feedback with stakeholders, different applications are planned that demonstrate the use of the climate data (e.g. Vanderhoeven et al., 2017).
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CORDEX.be Final Report. Combining regional downscaling expertise in Belgium: CORDEX and beyond
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Atmospheric Corrections and Multi-Conditional Algorithm for Multi-Sensor Remote Sensing of Suspended Particulate Matter in Low-to-High Turbidity Levels Coastal Waters
- The accurate measurement of suspended particulate matter (SPM) concentrations in coastal waters is of crucial importance for ecosystem studies, sediment transport monitoring, and assessment of anthropogenic impacts in the coastal ocean. Ocean color remote sensing is an efficient tool to monitor SPM spatio-temporal variability in coastal waters. However, near-shore satellite images are complex to correct for atmospheric effects due to the proximity of land and to the high level of reflectance caused by high SPM concentrations in the visible and near-infrared spectral regions. The water reflectance signal (ρw) tends to saturate at short visible wavelengths when the SPM concentration increases. Using a comprehensive dataset of high-resolution satellite imagery and in situ SPM and water reflectance data, this study presents (i) an assessment of existing atmospheric correction (AC) algorithms developed for turbid coastal waters; and (ii) a switching method that automatically selects the most sensitive SPM vs. ρw relationship, to avoid saturation effects when computing the SPM concentration. The approach is applied to satellite data acquired by three medium-high spatial resolution sensors (Landsat-8/Operational Land Imager, National Polar-Orbiting Partnership/Visible Infrared Imaging Radiometer Suite and Aqua/Moderate Resolution Imaging Spectrometer) to map the SPM concentration in some of the most turbid areas of the European coastal ocean, namely the Gironde and Loire estuaries as well as Bourgneuf Bay on the French Atlantic coast. For all three sensors, AC methods based on the use of short-wave infrared (SWIR) spectral bands were tested, and the consistency of the retrieved water reflectance was examined along transects from low- to high-turbidity waters. For OLI data, we also compared a SWIR-based AC (ACOLITE) with a method based on multi-temporal analyses of atmospheric constituents (MACCS). For the selected scenes, the ACOLITE-MACCS difference was lower than 7%. Despite some inaccuracies in ρw retrieval, we demonstrate that the SPM concentration can be reliably estimated using OLI, MODIS and VIIRS, regardless of their differences in spatial and spectral resolutions. Match-ups between the OLI-derived SPM concentration and autonomous field measurements from the Loire and Gironde estuaries’ monitoring networks provided satisfactory results. The multi-sensor approach together with the multi-conditional algorithm presented here can be applied to the latest generation of ocean color sensors (namely Sentinel2/MSI and Sentinel3/OLCI) to study SPM dynamics in the coastal ocean at higher spatial and temporal resolutions.
